Baby bottles with attached flexible nipples are commonly used to feed babies formula, water, and other liquids. The basic bottle is a hard bottle, such as a glass or plastic bottle, that is sterilized and filled with liquid. A nipple is then attached to the bottle and the assembly is ready for use. The nipple can include, for example, a threaded section to be directly attached to the bottle. Alternatively, a separate retaining ring can be used to affix the nipple to the bottle.
A popular alternative to a hard bottle is the disposable liner (also referred to as a "disposable bottle") used in conjunction with a support or holder. The liner comes pre-sterilized and is inserted into the holder. The liner is then filled with liquid, and the nipple is usually attached to the holder by a retaining ring, as discussed above. When a liner is used, the nipple or retaining ring typically is also used to secure the liner to the bottle assembly.
The use of a separate retaining ring has certain advantages. One such advantage is that the separate retaining ring can be made of different, sturdier material than that of the nipple. However, many consumers prefer the ease and simplicity of a one-piece unit, which minimizes the number of pieces that must be, for example, cleaned or packed for trips. Thus, various attempts have been made in the art to provide one-piece nipple and retaining ring as a unit.
As discussed above, the nipple itself may have a threaded flange for direct connection to the bottle. Such structures are typically not sturdy enough to endure heavy sucking or repeated use, and are conducive to leakage and spills. Other attempts have been made to adhere nipples to retaining rings. These designs have also been subject to leakage and spills, as the separate pieces tend to pull apart over time.
Accordingly, there is a need for a one piece nipple/ring that is formed of two different materials, yet is securely bonded or integrally formed to provide enhanced durability.